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Oct. 1, 2012 -- There is more evidence that sitting may be harmful to your health.

Studies suggest that people who sit for prolonged periods every day have a higher risk for diabetes, heart attack, and even some cancers.

Now new research finds that sitting for long stretches may also raise the risk for chronic kidney disease, especially in women.

Prolonged Sitting and Kidney Disease

Women in the study who reported less than three hours a day of total sitting time were 30% less likely to develop chronic kidney disease than those who reported spending more than eight hours a day in their chairs.

Prolonged sitting also appeared to be linked to increased risk for kidney disease in men, but to a lesser degree.

Regular physical activity, such as walking for 30 minutes a day, was associated with a reduced risk for developing kidney disease in men, but not in women.

This finding suggests that exercising to offset the negative impact of long periods of sitting may be more effective for men than women, says researcher Thomas Yates, MD. He is a senior lecturer in physical activity, sedentary behavior, and health at the University of Leicester in the United Kingdom.

“It may be more important for women to avoid sitting for long periods in the first place,” he says.

1 in 10 Adults Has Kidney Disease

The kidneys filter blood to remove waste products and make urine.

About 10% of adults in the U.S., or more than 20 million people, have chronic kidney disease, which is characterized by poor kidney function that develops over time.

People with kidney disease are at increased risk for developing heart disease, anemia, bone disease, and other health problems.

The study included about 6,000 adults who provided information about the amount of time they spent sitting each day and the amount of moderate to vigorous exercise they got.

People who sat the least had the lowest risk for developing chronic kidney disease, regardless of whether they exercised regularly or were overweight or obese.

The study, which appears in the October issue of the American Journal of Kidney Diseases, is the first to examine the impact of prolonged sitting on chronic kidney disease.

Sitting Too Much May Be Hazardous to Your Health

It also adds to the evidence suggesting that lifestyle plays an important role in kidney disease, and that prolonged sitting has a negative impact on health in general, Yates says.

Marc Hamilton, PhD, of the Pennington Biomedical Research Center, has studied the topic for more than a decade. He says it is increasingly clear that prolonged sitting is bad for everyone, whether they are fit or fat or active or inactive.

“The experimental studies conducted by us and others are consistent in finding that sitting too much is unhealthy, even in people who are not overweight and those who exercise regularly,” he says.

But it is not yet clear if getting up every half hour or so makes a difference, Hamilton says.

His own research suggests that when people do sit for long periods -- either at their desk at work or watching TV at home -- they aren’t completely inactive. In fact, they tend to spend about 40% of the time moving around.

“I’m not sure it’s all that helpful to tell people with desk jobs to get up and move around, because they are already doing that,” he says.